The present invention relates to image processing methods and apparatus applicable to game devices which advance a game on a real time basis by displaying an image on a display, and more particularly to an image processing method and apparatus which effectively uses the hardware resources of a game device.
Generally, a computer game device which is capable of processing a game on a real time basis includes a game device body which utilizes pre-stored game software, a control unit which gives an operational signal used for processing which includes movement of a character in a game, a display which displays an image which expresses images in the development of a game contained in the game device body, and an acoustic unit which generates the necessary sound as the game proceeds.
Game devices having a clear display screen to providing a more realistic image are popular. Particularly, game devices which use polygon processing are popular as they are capable of expressing three-dimensional image data as a collection of given units providing high visual reality. In a game device using polygon processing, the number of polygons which constitutes an object (a displayed object movable on the display screen) is increased and the polygon surfaces are coated with a texture to thereby further enhance a realistic image.
As just described above, the demand for increasingly more realistic images requires that hardware should have an ability to reduce processing time as well as to process a greatly increased quantity of data on a real time basis, so that the load on the hardware is greatly increased. This demand is expected to continuously increase in the future, thereby increasing the operational load on the hardware.
First of all, the game device is required to perform real-time image processing on the basis of data input by the player, with the basic load on the central processing unit being essentially high compared to sole computer graphics image processing.
In addition, if a game device is composed of a plurality of expensive high-speed operation devices in order to ensure an overwhelming data processing ability such as is present in a flight simulator, the game device would be an expensive commodity and would not satisfy the needs of the market.
As such, conventional game devices must perform image display processing, whilst limiting the processing ability of its processor or the amount of its data capacity. Thus, the resulting image would give insufficient reality to viewers.
In view of the problems with the conventional techniques, it is an object of the present invention to provide an image processing method and apparatus which is capable of reducing the image processing load and displaying an image having greater reality.
Another object of the present invention is to provide an image processing method and apparatus which is capable of reducing the image processing load of an object to be displayed in order to thereby display an image having greater reality.
In order to achieve the above objects, in an image processing method according to the present invention, rotational components of a matrix of an object obtained by coordinate conversion involving a matrix of information on a virtual camera and a version matrix is set so as to form a unit matrix to thereby provide data for the display of the object. The matrix of camera information includes, for example, information on the position and rotation of the camera.
The virtual camera can be compared to a regular camera in that the former has a viewpoint and an image angle involving the delineation of computer graphics. The virtual camera is set by designation of its position, optical axis direction (direction of its lens), image angle (zoom-wide), and twist (rotational angle around the optical axis). In other words, the virtual cameral implies a virtually set viewpoint. The virtual camera can be understood as a visual field direction determination means which determines the visual field direction of the image displayed on the video monitor. The object is modeling-converted from a body coordinate system inherent in a figure (object) to a world coordinate system which defines the disposition of the figure in a three-dimensional space. The resulting object image is visual field-converted to one belonging to a visual-field coordinate system determined by (the position and angle) of the virtual camera, with this object image being displayed on the monitor 30.
In addition, preferably, rotational components of a matrix given by
X=TM
which contains information on the travel or movement of an object in a three-dimensional space, where M is a matrix of information on a virtual camera and T is a conversion matrix, are set so as to form the components of a unit matrix to thereby obtain data on the display of the object which faces in an eye direction at all times.
An image processing apparatus according to the present invention includes processing means for performing coordinate conversion of the object on the basis of a matrix of information of a virtual camera and for setting the rotational components of the matrix of the coordinate-converted object as components which compose a unit matrix.
The processing means includes, for example, camera control matrix processing means for obtaining the matrix of information of a virtual camera, and object matrix processing means for obtaining a matrix of information on a point rotated on the basis of the product of the matrix of information of a virtual camera and the conversion matrix and for setting the rotational components of the matrix so as to compose a unit matrix to thereby obtain data relating to the display of the object which faces in the eye direction of the virtual camera at all times.
An image processing apparatus according to the present invention includes storage means for storing information on the position coordinates and angle of a camera and information on the position coordinates of an object, and object matrix processing means for calculating each angle of a three-dimensional coordinate system which causes the object to face in a desired direction on the basis of the information on the position coordinates and angle of the camera and the information on the position coordinates of the object, obtained from the storage means.
In the inventive image processing, the rotational components of the display matrix of the object obtained by the coordinate conversion are set so as to compose a unit matrix. Thus, data on the display of the object which faces in the eye direction of the virtual camera is created at all times. Even when the virtual camera is facing in any direction, the relationship between the camera and the object is such that the object faces the camera at all times. Thus, required data on the object is only (two-dimensional) data to the front of the object, a large amount of data is not required to be handled. Accordingly, the workload of the operation is kept light. The object may be composed of object data displayed in the form of a panel. In addition, this object can be set so as to face in a predetermined direction at all times at a predetermined position. A flat object such as a signboard can be set so as to face in the eye direction at all times. As for the matrix of information on the camera, information on the position and rotation of the camera is selectable depending on information on the operation of the game device as requested.